The length of a rectangle is 8cm greater than its width. How do you find the dimensions of the rectangle if its area is 105cm²?

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Answer 1 · 2018-04-01T03:13:09

Dimensions: #15#cm #xx# #7# cm

Let the length of the rectangle be #l# and the width of the rectangle be #w#,

#l*w=105#

#l=w+8#

Substitute #l=w+8# into #l*w=105#,

#(w+8)*w=105#

Expand,

#w^2+8w-105=0#

Factor,

#(w-7)(w+15)=0#

Solve,

#w=7 or cancel(-15# ( reject #-15# as #w>0# )

When #w=7#,

#l=7+8#
#l=15#

Hence, the length is #15#cm and the width is #7#cm.